1. Field of the Invention
The invention relates generally to systems for the transport and treatment of sewage.
2. Description of Prior Art
Two types of sewage treatment systems currently exist. The first is a sewage treatment plant system found most commonly in cities and more densely populated areas. The other is a septic tank system used in more rural and less populated areas. Each system has its disadvantages which become apparent over time.
In a sewage treatment plant system, sewage from a source, such as a home or building, travels via sewer lines directly to a sewage treatment plant where both the solid and liquid components of the sewage are treated. Many problems with existing sewage treatment plant systems are caused by the transport and treatment of solid sewage.
The transport of solid matter via sewer lines typically requires pumping equipment due to lack of gravity flow. Providing and using such equipment can be quite costly. If pumps malfunction or an excessive amount of solid waste exists, the solid matter may cause blockage in the sewer lines. In order to minimize blockage of solid matter, sewer lines tend to be large in diameter and consequently expensive.
Sewage treatment plants carry the great burden of receiving and treating all sewage coming directly from the sources. If excessive sewage is transported to the treatment plant, the treatment plant may overflow. Consequently, sewage enters and pollutes nearby rivers, bays and oceans, contaminating the waters and their organisms. The only way of preventing overflow thus far has been to either increase the capacity of the existing sewage treatment plant or develop an additional plant.
Furthermore, the treatment of solid sewage in a treatment plant incurs major costs. The prior art includes aerobic treatment, such as trickling filters, oxidation ponds and activated sludge processes, as well as tertiary sewage treatment through use of chemicals such as phosphates and inorganic contaminants. Use of these processes can consume a great deal of energy. Also, providing the necessary equipment to facilitate these processes is expensive. Therefore, what is needed is a system and a method for minimizing the transport of solid waste to sewage treatment plants, thereby reducing the amount of solid waste to be treated therein.
In a septic tank system, the septic tank functions to filter and treat the solid matter while the liquid sewage flows out from the septic tank via an effluent line to a leach field where the liquid matter is absorbed. Septic tanks are most commonly found in rural or outback areas away from downtown, urban areas. As rural areas become more densely populated, it becomes less feasible for each home or building to have its own septic tank and leach field. Consequently, the only solution being provided for a growing area having septic tanks is to develop a new sewage treatment plant that will accommodate the new sources of waste. Eventually, sewage treatment plants in rural areas will face the same problems as those in the city as demand exceeds the plants"" capacities.
Sewage systems with septic tanks also exert great demand on the leach fields. In such a system, the septic tank filters out the solid matter while the liquid matter passes through the effluent line to the leach field. Since none of the liquid matter is treated, all of the liquid sewage travels from the septic tank to the leach field where the liquid sewage gets absorbed. If the leach field should become saturated, for example during times of heavy rainfall or excessive usage, it will be unable to absorb any more incoming liquid sewage, which could then overflow into and contaminate surrounding areas.
In accordance with the present invention, both a system and method are disclosed which overcome these obstacles in the transport and treatment of sewage. A source of solid and liquid waste is coupled to a septic tank by an influent line. The septic tank is coupled to a sewage treatment plant by an outlet line, which may comprise an indefinite number of intermediary lines and valves. In the preferred embodiment, the outlet line comprises an effluent line coupled to the septic tank and a distribution line coupled to the sewage treatment plant. A valve may be disposed between the effluent line and the distribution line. The valve may be coupled to a leach field.
In operation, solid and liquid matter travel from the source to the septic tank. The septic tank filters out solid matter. Liquid matter passes through the septic tank and travels through the outlet line to the sewage treatment plant to be treated. Where a valve is coupled to a leach field and provided in between an effluent line and a distribution line, the liquid matter travels through the effluent line to the valve. The valve may then direct the liquid matter to the distribution line where the liquid matter is transported to the sewage treatment plant, or to the leach field where the liquid matter is absorbed.
The invention also comprises additional septic tank systems all coupled with the sewage treatment plant. The distribution lines of additional retrofitted septic tank systems may be coupled either directly or indirectly to the sewage treatment plant. In the case where the distribution lines are indirectly coupled to the sewage treatment plant, the distribution lines may be coupled to the valves of other retrofitted septic tank systems.
The invention also comprises methods for retrofitting a septic tank system, retrofitting a sewage treatment plant system, building a new sewage system, and transporting and treating sewage waste. The commonality between all these methods includes: transporting solid and liquid waste from a source to a septic tank; filtering out solid waste from the liquid waste with the septic tank; and transporting the liquid waste from the septic tank to a sewage treatment plant.
Many benefits result from the combination of a septic tank with a sewage treatment plant. Some of those benefits include minimizing the transport of solid waste to the sewage treatment plant, thus minimizing transport problems and reducing equipment costs. The invention also minimizes the treatment of solid waste by the sewage treatment plant, thereby reducing chemical and equipment costs as well as decreasing the potential for overflow and sewage pollution. Many more benefits will become readily apparent as this invention is applied to retrofit existing sewage systems.
The invention, now having been briefly summarized, may be better visualized by turning to the following drawings wherein like elements are referenced by like numerals.